In recent years, network systems are widely used in which a plurality of information processing apparatuses and the like are connected to be mutually communicable via the communication networks such as the Internet (hereinafter simply referred to as “network”).
In such a network system, various types of data are transmitted and received between pluralities of information processing apparatuses. For this reason, processing load related to data communication may concentrate on such an information processing apparatus as a server providing a certain service. In addition, there may be cases in which communication data concentrates on a certain communication route on a network, and causes a delay on the communication route. In such cases, the communication qualities such as the communication responsiveness and real-time characteristics may be degraded.
So as to prevent degradation of communication qualities caused by the above-mentioned concentration of communication data, such countermeasures as selecting one of a plurality of communication routes which has not caused any delay, or multiplexing a certain communication route, can be considered.
The following patent literatures are examples of related technologies with regard to such communication quality problems.
PTL 1 discloses a technology related to a communication route selecting system and the like in which a transmitter of a communication packet can dynamically select a transfer route of the communication packet.
The technology disclosed in PTL 1 registers a plurality of communication routes to a same communication destination, on a routing table, and measures a packet round-trip time for each communication route. The technology disclosed in PTL 1 realizes load balancing to the network by selecting a communication route based on the measured round-trip time. In other words, the technology disclosed in PTL 1 can prevent concentration of load to a certain communication route by selecting a route on which the response time is short.
PTL 2 discloses a technology related to a packet transmitting system and the like that connects the packet transmitting and receiving apparatuses using a plurality of communication routes and transmits and receives a multiplexed packet via a plurality of communication routes.
The technology disclosed in PTL 2 divides data to be transmitted into packets of a certain length, assigns serial packet numbers to the packets, and copies each packet and transmits the copied packets in parallel from a plurality of communication routes. The technology disclosed in PTL 2 rearranges the packets so that only one copy of the same packet included in each copied transmission packet sequence exists on the same communication route, and that copies of the same packet are not transmitted concurrently from any communication route.
The technology disclosed in PTL 2 enables multiplexing of communication routes, as well as ensuring reliability of the communication routes by recovering the communication error in packet transfer.